Yaa ..the study guide will be enough for exam point of view. But to have a deep knowledge u need to download some documents and read.. Go thru books like DBA hand book,Backup and recovery by Anand adkoli and Ram velpuri....I have done Fundamentals 1..By reading theses books only..But 99.99% were asked from study guide. Go thru dumps also....Gonna give 1z007 next week..heard tat study guide will be enough for that 2....Let me see...mail u after finishing tat exam.....
The concepts manual tells gives you a grounding in how Oracle works and what you can expect from it. It does not provide detailed information on many of the features it discusses. As such, I would expect you to fail if this were your only reference.
If you use the study guides, these usually contain a mix of the concepts and the details in the correct proportions to get you through the exam.
Note. I'm talking here about passing the exams, not becoming a competant DBA. As a good DBA you will be constantly referring to the manuals, including the concepts manual, for the rest of your career.